Examples in the prior art of electric-powered self-balancing vehicles for use while standing include those disclosed in U.S. Pat. No. 6,302,230 issued to Kamen et al. for Personal Mobility Vehicles and Methods (the '230 patent), and U.S. patent application Ser. No. 12/281,101 by Simeray for Motorized Transport Vehicle for a Pedestrian (the '101 application).
In a powered self-balancing unicycle, an electronic gyroscope that accelerates or decelerates the wheel in the appropriate direction is used to achieve fore-and-aft balance. This type of automatic fore-and-aft balance technology is taught in the '230 patent. A sensor and the electronic gyroscope equipment are provided. Position information detected by the sensor and the electronics is relayed to a motor. The motor drives the wheel in the appropriate direction and at sufficient speed to maintain fore-and-aft balance.
The '230 patent includes two-wheel and one-wheel embodiments, the two-wheel embodiment including the “Segway”, a highly-publicized personal transport device having a user platform between (or above) two parallel wheels. Among the one-wheel embodiments in the '230 patent are some which, like the present invention, do not include a handle bar support by a shaft. However, since these do not provide any means for stabilizing the device with respect to the user's legs, they would require considerable skill to use, in addition to being difficult to control precisely.
It is greatly conducive to the comfort and safety of using the device if there is some means for stabilizing the device with respect to the user's legs, especially in situations where more precise control may be required, such as when mounting or dismounting, executing turns, passing over bumps in the riding surface, or keeping the device upright when ascending or descending a slope. Thus without specific considerations in the design of the vehicle for this purpose, this type of device would not be practical as a means of transportation.
The '101 application teaches a single wheel, coupled to a frame to which two platforms (one on each side of the wheel) are attached. One of the defining features of the '101 application is its “guide supports that tightly hold the user's legs”. These guide supports are shown as brackets in the form of bars or cuffs which hold the legs at knee or calf level and restrict the range of forward or backward leaning of the legs relative to the wheel, thereby providing greater stability for the user. Many embodiments of the '101 application therefore generally meet the needs described above, since the user can press against the leg brackets for stability and for steering and tilting the device. However, the restraints imposed by the leg brackets introduce some inconvenience and, in some situations, danger in using the device, since when the user needs to dismount quickly the brackets may prevent him from doing so. There is therefore a need for an alternative means of achieving the same functions.